ONE of Ed Miliband's most senior MPs has warned Labour must put more effort into translating the party's flagship principles into coherent policies.

Shadow Defence Secretary Jim Murphy made his comments amid fears that voters do not know what the Labour leader's One Nation slogan stands for in practice.

However, he defended Mr Miliband, who has also come under pressure following polls suggesting the party's lead over the Tories is narrowing and his attempts to modernise its links to the trade unions.

Mr Murphy, speaking before the start of Labour's conference in Brighton on Sunday, insisted Mr Miliband was starting to get the One Nation theme across.

But the East Renfrewshire MP suggested there were some frontbench colleagues who had to play "catch up".

Asked if enough had been done to help voters understand what One Nation means in policy terms, Mr Murphy said: "In the last year Ed Miliband and his team have made a great deal of progress on that."

However, he added: "There are others of us who have to catch up with that and put as much effort and energy into it as Ed does".

Asked if by others he meant other members of Labour's frontbench he said: "Yes".

Mr Murphy insisted he was confident the electorate would know exactly what the party stood for at the 2015 general election campaign. By then, he said, "the public will know, and you will see a lot of that at conference".

Mr Miliband used last year's Labour conference to successfully debut his One Nation slogan.

It was initially credited with drawing a line under speculation over his leadership. But there have been increasing calls in recent months for the party to put more meat on the bones of the idea.

In August, Labour's shadow health secretary Andy Burnham called on the party to "put its cards on the table" and develop attention grabbing policies, although he stressed he had the utmost respect for Mr Miliband.

Veteran backbencher George Mudie also said he did not know what his own party stood for in key areas, including health, education and welfare.

Earlier this week, former Home Secretary Jacqui Smith likened the party's policy review process to the Edinburgh Zoo panda pregnancy, suggesting it had so far promised much and delivered little.

Labour's focus at conference will be on the cost of living, warning that price rises continue to outpace wages.

The Conservatives have claimed the party's credibility on the economy has been damaged by the recent upturn. But Mr Murphy dismissed ­predictions that greater economic growth would damage Labour's chances of winning in 2015.

The election would be decided on whichever party offered voters a better future, he said, adding that offering "more of the same will not win".

Mr Murphy also dismissed the Conservatives and LibDems, accusing Nick Clegg's party, whose conference was held in Glasgow this week, of "playing for a draw" to form part of another coalition government. He said Labour was out to win, and added: "The only time you might play for a draw is when you are playing away to Barcelona. We are not playing away to Barcelona, and David Cameron is no Lionel Messi."

Mr Murphy said he was right to back Mr Miliband after he accused the Unite union of overstepping the mark in the recent Falkirk constituency selection process row.

He said: "I think I was right to back Ed Miliband on Falkirk and I will continue to do so as he tries to modernise the relationship between the Labour party and the trade unions".